1.The Dual Role of p21 in Hormone-related Cancers and Its Therapeutic Implications
Jia-Wen LI ; Yang CHEN ; Jia-Qi WANG ; Yu-Kai MA ; Zhi-Yi GUO
Progress in Biochemistry and Biophysics 2026;53(3):593-608
p21 (encoded by the CDKN1A gene) is a critical cell cycle regulatory protein endowed with versatile biological functions. In various sex hormone-related cancers, p21 exhibits a paradoxical dual role, capable of both inhibiting tumorigenesis and promoting cancer progression, exerting dual, often opposing, effects on cellular fate that are dictated by the specific context. The clinical targeting of p21 remains elusive, largely due to its functionally pleiotropic and context-dependent nature within intricate regulatory networks. During the initial, hormone-dependent phase of cancers like breast and prostate cancer, p21 expression and activity are largely governed by the transcriptional programs of estrogen or androgen receptor signaling. This hormonal regulation contributes to the control of tumor cell proliferation and underpins the initial efficacy of endocrine therapies. In contrast, as these diseases advance to late stages or evolve into non-hormone-dependent subtypes—exemplified by castration-resistant prostate cancer (CRPC) and specific forms of triple-negative breast cancer (TNBC)—these conventional hormonal control mechanisms often become dysfunctional or are entirely bypassed. This fundamental transition creates a critical therapeutic void, highlighting the urgent need to identify and exploit alternative molecular pathways to effectively target p21’s function. Promising strategies may include the precise modulation of its upstream transcriptional regulators, downstream effector proteins, or the intersecting parallel signaling networks that critically influence its activity. This review provides a systematic synthesis of the intricate and interconnected mechanisms that underpin the dual effects of p21 in sex hormone-related tumors. These mechanisms are categorized into three core, interrelated functional domains. (1) cell cycle regulation: p21 executes its canonical tumor-suppressive role by binding to and inhibiting cyclin-dependent kinases (CDKs) and by directly interacting with proliferating cell nuclear antigen (PCNA), thereby inducing cell cycle arrest, predominantly at the G1/S checkpoint; (2) apoptosis modulation: p21 exerts a highly context-dependent influence on programmed cell death, functioning either as a pro-apoptotic agent under severe genotoxic stress or as a pro-survival factor by inhibiting apoptosis through interactions with proteins like Bcl-2; (3) hormonal and signaling crosstalk: p21 is an integral node within broader cellular networks, engaging in direct physical interactions with hormone receptors(e.g., AR, ER) and participating in complex feedback loops with key oncogenic pathways, including PI3K/AKT, MAPK/ERK, and p53. Critically, the role of p21 is not static but highly dynamic. It can undergo a functional switch from tumor-suppressive to tumor-promoting in response to therapeutic pressures, metabolic alterations, or evolving tumor microenvironment cues. These adaptive shifts are frequently implicated in the development of therapy resistance and disease recurrence, particularly in advanced, hormone-resistant cancers. By synthesizing these insights, this review aims to establish a coherent theoretical framework to guide the future development of novel therapeutic strategies that target the p21 pathway. It underscores the necessity of moving beyond a simplistic, binary view of p21 and emphasizes the forthcoming challenges, such as the discovery of reliable biomarkers to predict its functional state and the rational design of context-specific pharmacological modulators to selectively harness its therapeutic potential.
2.Herbal Textual Research on Quisqualis Fructus in Famous Classical Formulas
Xiuping WEN ; Shiying CHEN ; Ying TAN ; Guanwen ZHENG ; Huilong XU ; Wen XU ; Chengzi YANG ; Zehao HUANG ; Yu LIN ; Zhilai ZHAN
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(6):225-237
This article systematically analyzed the historical evolution of the origin, scientific name, producing area, quality evaluation, harvesting and processing, and other aspects of Quisqualis Fructus by consulting the ancient materia medica, medical books, prescription books, local literature and combining with the modern literature and standards, summarized and explored the development rules of its medicinal properties and efficacy along with their underlying causes, in order to provide support for the development and utilization of famous classical formulas containing this herb. According to the textual research, Shijunzi was first recorded as Liuqiuzi in Nanfang Caomuzhuang of the Jin dynasty, and the name of Shijunzi was first used in Kaibao Bencao of the Song dynasty, which has been consistently used throughout subsequent dynasties, and there were also aliases such as Junziren, Sijunzi, and Dujilizi. The mainstream source of Quisqualis Fructus used in the past dynasties has been the dried mature fruits of Quisqualis indica, a plant belonging to the family Combretaceae. In modern times, its variety Q. indica var. villosa has also been recorded as the medicinal material of Quisqualis Fructus. In 2007, the Flora of China(English edition) designated Q. indica var. villosa as a synonym of Q. indica. Today, the accepted name of Shijunzi is updated to Combretum indicum. According to ancient herbal records, the producing areas of Quisqualis Fructus were Guangdong, Hong Kong, Macao, Guangxi, Hainan, Sichuan and Fujian, and then gradually expanded to Yunnan, Taiwan, Jiangxi and Guizhou. Since the Song dynasty, two major production regions have gradually emerged in Sichuan, Chongqing and Fujian. Currently, it is primarily cultivated in Chongqing, Guangxi and other areas, with Chongqing yielding the highest output. Since modern times, superior quality has been defined by large size, a purple-black surface, plump grains, and a yellowish-white kernel. According to ancient herbal records, the harvesting period of Quisqualis Fructus was the July and August of the lunar calendar, mostly used raw after shelling or with the shell intact, it underwent processing methods such as cleaning, slicing, mixing, steaming, roasting, stewing, and frying. Currently, the harvesting period is autumn, followed by sun-drying or low-heat drying, with processing methods including cleaning, stir-frying, and stewing. In ancient and modern literature, the records of the properties, functions and indications of Quisqualis Fructus are basically the same, that is, sweet in taste, warm in nature, predominantly non-toxic, belonging to the spleen and stomach meridians. It possesses effects of insecticide, decontamination and invigorating spleen for ascariasis, enterobiasis, abdominal pain due to worm accumulation and infantile malnutrition.The contraindications for use primarily include avoiding consumption by individuals without parasitic infestations, limiting use for those with spleen-stomach deficiency-cold, refraining from drinking hot tea during medication, and avoiding excessive intake. Based on the textual research, it is suggested that the dried mature fruits of Q. indica should be used as the medicinal material for the development of famous classical formulas containing Quisqualis Fructus. Processing methods may be chosen according to prescription requirements, and the raw products is recommended for medicinal use if not specified.
3.Effects of verbascoside on liver damage and TLR4/NF-κB signaling pathway in D-galactose-induced aging mice
Chong MA ; Qian-qian WANG ; Ruo-yu GENG ; Li-mei WEN ; Jian-hua YANG ; Jun-ping HU
Chinese Traditional Patent Medicine 2025;47(9):2888-2893
AIM To investigate the protective effects of verbascoside on D-galactose-induced liver injury in mice and its underlying mechanisms.METHODS C57BL/6J mice were randomly assigned to the normal group,the model group,the vitamin E group(100 mg/kg),and the low-dose and high-dose verbascoside groups(40,80 mg/kg),with 10 mice in each group.Simultaneous administration of medicine and subcutaneous injection of D-galactose(600 mg/kg)went on among the groups except the normal group for 8 weeks.Serum ALT,AST,ALP activities,along with TBil levels were measured using biochemical kits.Hepatic GSH,MDA concentrations,as well as SOD and GSH-Px activities were quantified.Liver pathological morphology was evaluated by HE staining,while hepatic fibrosis area was assessed using Sirius red staining.Western blot analysis determined hepatic expression of IL-6,IL-1β,TNF-ɑ,TLR4,NF-κB p65,IκBɑ and p-IKBɑ proteins.RESULTS Compared to the model group,the groups treated with vitamin E or verbascoside demonstrated significantly reduced body weight(P<0.05,P<0.01);increased hepatic index(P<0.05,P<0.01);decreased serum activities of ALT,AST and ALP alongsided reduced TBil levels(P<0.05,P<0.01);attenuated pathological damage of liver tissue and fibrosis severity;reduced hepatic MDA level(P<0.05,P<0.01);and elevated GSH level with enhanced SOD and GSH-Px activities(P<0.05,P<0.01).Furthermore,the high-dose verbascoside group showed significantly decreased hepatic expressions of IL-6,IL-1 β,TNF-ɑ,TLR4,NF-κB p65,and p-IKBɑ/IKBɑ proteins(P<0.05,P<0.01).CONCLUSION Verbascoside improves D-galactose-induced liver injury through its antioxidant activity,anti-inflammatory effects,and suppression of the TLR4/NF-κB signaling pathway.
4.Research progress on kinesiophobia in school-aged children with asthma and nursing enlightenment
Zhixiang SUN ; Jing FU ; Pingpin WEN ; Xiaoli ZHANG ; Xinyu YANG ; Chunyan LIU ; Yu XIAO
Chinese Journal of Nursing 2025;60(19):2419-2425
Kinesiophobia is prevalent among school-aged children with asthma,and severe kinesiophobia can hinder their participation in physical activities and disease control,adversely affecting their physical and mental health.This paper reviews the concept,development,assessment tools,influencing factors,and intervention strategies of kinesiophobia in school-aged children with asthma,analyzes existing challenges,and proposes directions for future research.It aims to provide insights for developing scientific and personalized intervention plans to enhance children's exercise levels and improve their quality of life.
5.Aldolase A accelerates hepatocarcinogenesis by refactoring c-Jun transcription
Xin YANG ; Guang-Yuan MA ; Xiao-Qiang LI ; Na TANG ; Yang SUN ; Xiao-Wei HAO ; Ke-Han WU ; Yu-Bo WANG ; Wen TIAN ; Xin FAN ; Zezhi LI ; Caixia FENG ; Xu CHAO ; Yu-Fan WANG ; Yao LIU ; Di LI ; Wei CAO
Journal of Pharmaceutical Analysis 2025;15(7):1634-1651
Hepatocellular carcinoma(HCC)expresses abundant glycolytic enzymes and displays comprehensive glucose metabolism reprogramming.Aldolase A(ALDOA)plays a prominent role in glycolysis;however,little is known about its role in HCC development.In the present study,we aim to explore how ALDOA is involved in HCC proliferation.HCC proliferation was markedly suppressed both in vitro and in vivo following ALDOA knockout,which is consistent with ALDOA overexpression encouraging HCC prolifera-tion.Mechanistically,ALDOA knockout partially limits the glycolytic flux in HCC cells.Meanwhile,ALDOA translocated to nuclei and directly interacted with c-Jun to facilitate its Thr93 phosphorylation by P21-activated protein kinase;ALDOA knockout markedly diminished c-Jun Thr93 phosphorylation and then dampened c-Jun transcription function.A crucial site Y364 mutation in ALDOA disrupted its interaction with c-Jun,and Y364S ALDOA expression failed to rescue cell proliferation in ALDOA deletion cells.In HCC patients,the expression level of ALDOA was correlated with the phosphorylation level of c-Jun(Thr93)and poor prognosis.Remarkably,hepatic ALDOA was significantly upregulated in the promotion and progression stages of diethylnitrosamine-induced HCC models,and the knockdown of Aldoa strikingly decreased HCC development in vivo.Our study demonstrated that ALDOA is a vital driver for HCC development by activating c-Jun-mediated oncogene transcription,opening additional avenues for anti-cancer therapies.
6.Elemene as a binding stabilizer of microRNA-145-5p suppresses the growth of non-small cell lung cancer
Meirong ZHOU ; Jiayue WANG ; Yulin PENG ; Xiangge TIAN ; Wen ZHANG ; Junlin CHEN ; Yue WANG ; Yu WANG ; Youjian YANG ; Yongwei ZHANG ; Xiaokui HUO ; Yuzhuo WU ; Zhenlong YU ; Tian XIE ; Xiaochi MA
Journal of Pharmaceutical Analysis 2025;15(3):585-598
Elemene is widely recognized as an effective anti-cancer compound and is routinely administered in Chinese clinical settings for the management of several solid tumors,including non-small cell lung cancer(NSCLC).However,its detailed molecular mechanism has not been adequately demonstrated.In this research,it was demonstrated that elemene effectively curtailed NSCLC growth in the patient-derived xenograft(PDX)model.Mechanistically,employing high-throughput screening techniques and subsequent biochemical validations such as microscale thermophoresis(MST),microRNA-145-5p(miR-145-5p)was pinpointed as a critical target through which elemene exerts its anti-tumor effects.Inter-estingly,elemene serves as a binding stabilizer for miR-145-5p,demonstrating a strong binding affinity(dissociation constant(KD)=0.39±0.17 μg/mL)and preventing its degradation both in vitro and in vivo,while not interfering with the synthesis of the primary microRNA transcripts(pri-miRNAs)and precursor miRNAs(pre-miRNAs).The stabilization of miR-145-5p by elemene resulted in an increased level of this miRNA,subsequently suppressing NSCLC progression through the miR-145-5p/mitogen-activated pro-tein kinase kinase kinase 3(MAP3K3)/nuclear factor kappaB(NF-κB)pathway.Our findings provide a new perspective on revealing the interaction patterns between clinical anti-tumor drugs and miRNAs.
7.Objective characteristics of tongue manifestation in different stages of damp-heat syndrome in diabetic kidney disease
Zhaoxi DONG ; Yang SHI ; Jiaming SU ; Yaxuan WEN ; Zheyu XU ; Xinhui YU ; Jie MEI ; Fengyi CAI ; Xinyue ZANG ; Yan GUO ; Chengdong PENG ; Hongfang LIU
Journal of Beijing University of Traditional Chinese Medicine 2025;48(3):398-411
Objective:
To investigate the objective characteristics of tongue manifestation in different stages of damp-heat syndrome in diabetic kidney disease (DKD).
Methods:
A cross-sectional study enrolled 134 patients with DKD G3-5 stages who met the diagnostic criteria for damp-heat syndrome in DKD. The patients were treated at Dongzhimen Hospital, Beijing University of Chinese Medicine, from May 2023 to January 2024. The patients were divided into three groups: DKD G3, DKD G4, and DKD G5 stage, with 53, 33, and 48 patients in each group, respectively. Clinical general data (gender, age, and body mass index) and damp-heat syndrome scores were collected from the patients. The YZAI-02 traditional Chinese medicine (TCM) AI Tongue Image Acquisition Device was used to capture tongue images from these patients. The accompanying AI Open Platform for TCM Tongue Diagnosis of the device was used to analyze and extract tongue manifestation features, including objective data on tongue color, tongue quality, coating color, and coating texture. Clinical data and objective tongue manifestation characteristics were compared among patients with DKD G3-5 based on their DKD damp-heat syndrome status.
Results:
No statistically significant difference in gender or body mass index was observed among the three patient groups. The DKD G3 stage group had the highest age (P<0.05). The DKD G3 stage group had a lower score for symptoms of poor appetite and anorexia(P<0.05) than the DKD G5 group. No statistically significant difference was observed in damp-heat syndrome scores among the three groups. Compared with the DKD G5 stage group, the DKD G3 stage group showed a decreased proportion of pale color at the tip and edges of the tongue (P<0.05). The DKD G4 stage group exhibited an increased proportion of crimson at the root of the tongue, a decreased proportion of thick white tongue coating at the root, a decreased proportion of pale color at the tip and edges of the tongue, an increased hue value (indicating color tone) of the tongue color in the middle, an increased brightness value (indicating color lightness) of the tongue coating color in the middle, and an increased thickness of the tongue coating (P<0.05). No statistically significant difference was observed in other tongue color proportions, color chroma values, body characteristics, coating color proportions, coating color chroma values, and coating texture characteristics among the three groups.
Conclusion
Tongue features differ in different stages of DKD damp-heat syndrome in multiple dimensions, enabling the inference that during the DKD G5 stage, the degree of qi and blood deficiency in the kidneys, heart, lungs, liver, gallbladder, spleen, and stomach is prominent. Dampness is more likely to accumulate in the lower jiao, particularly in the kidneys, whereas heat evil in the spleen and stomach is the most severe. These insights provide novel ideas for the clinical treatment of DKD.
8.Impact of early detection and management of emotional distress on length of stay in non-psychiatric inpatients: A retrospective hospital-based cohort study.
Wanjun GUO ; Huiyao WANG ; Wei DENG ; Zaiquan DONG ; Yang LIU ; Shanxia LUO ; Jianying YU ; Xia HUANG ; Yuezhu CHEN ; Jialu YE ; Jinping SONG ; Yan JIANG ; Dajiang LI ; Wen WANG ; Xin SUN ; Weihong KUANG ; Changjian QIU ; Nansheng CHENG ; Weimin LI ; Wei ZHANG ; Yansong LIU ; Zhen TANG ; Xiangdong DU ; Andrew J GREENSHAW ; Lan ZHANG ; Tao LI
Chinese Medical Journal 2025;138(22):2974-2983
BACKGROUND:
While emotional distress, encompassing anxiety and depression, has been associated with negative clinical outcomes, its impact across various clinical departments and general hospitals has been less explored. Previous studies with limited sample sizes have examined the effectiveness of specific treatments (e.g., antidepressants) rather than a systemic management strategy for outcome improvement in non-psychiatric inpatients. To enhance the understanding of the importance of addressing mental health care needs among non-psychiatric patients in general hospitals, this study retrospectively investigated the impacts of emotional distress and the effects of early detection and management of depression and anxiety on hospital length of stay (LOS) and rate of long LOS (LLOS, i.e., LOS >30 days) in a large sample of non-psychiatric inpatients.
METHODS:
This retrospective cohort study included 487,871 inpatients from 20 non-psychiatric departments of a general hospital. They were divided, according to whether they underwent a novel strategy to manage emotional distress which deployed the Huaxi Emotional Distress Index (HEI) for brief screening with grading psychological services (BS-GPS), into BS-GPS ( n = 178,883) and non-BS-GPS ( n = 308,988) cohorts. The LOS and rate of LLOS between the BS-GPS and non-BS-GPS cohorts and between subcohorts with and without clinically significant anxiety and/or depression (CSAD, i.e., HEI score ≥11 on admission to the hospital) in the BS-GPS cohort were compared using univariable analyses, multilevel analyses, and/or propensity score-matched analyses, respectively.
RESULTS:
The detection rate of CSAD in the BS-GPS cohort varied from 2.64% (95% confidence interval [CI]: 2.49%-2.81%) to 20.50% (95% CI: 19.43%-21.62%) across the 20 departments, with a average rate of 5.36%. Significant differences were observed in both the LOS and LLOS rates between the subcohorts with CSAD (12.7 days, 535/9590) and without CSAD (9.5 days, 3800/169,293) and between the BS-GPS (9.6 days, 4335/178,883) and non-BS-GPS (10.8 days, 11,483/308,988) cohorts. These differences remained significant after controlling for confounders using propensity score-matched comparisons. A multilevel analysis indicated that BS-GPS was negatively associated with both LOS and LLOS after controlling for sociodemographics and the departments of patient discharge and remained negatively associated with LLOS after controlling additionally for the year of patient discharge.
CONCLUSION
Emotional distress significantly prolonged the LOS and increased the LLOS of non-psychiatric inpatients across most departments and general hospitals. These impacts were moderated by the implementation of BS-GPS. Thus, BS-GPS has the potential as an effective, resource-saving strategy for enhancing mental health care and optimizing medical resources in general hospitals.
Humans
;
Retrospective Studies
;
Male
;
Length of Stay/statistics & numerical data*
;
Female
;
Middle Aged
;
Adult
;
Psychological Distress
;
Inpatients/psychology*
;
Aged
;
Anxiety/diagnosis*
;
Depression/diagnosis*
9.The regulation and mechanism of apolipoprotein A5 on myocardial lipid deposition.
Xiao-Jie YANG ; Jiang LI ; Jing-Yuan CHEN ; Teng-Teng ZHU ; Yu-Si CHEN ; Hai-Hua QIU ; Wen-Jie CHEN ; Xiao-Qin LUO ; Jun LUO
Acta Physiologica Sinica 2025;77(1):35-46
The current study aimed to clarify the roles of apolipoprotein A5 (ApoA5) and milk fat globule-epidermal growth factor 8 (Mfge8) in regulating myocardial lipid deposition and the regulatory relationship between them. The serum levels of ApoA5 and Mfge8 in obese and healthy people were compared, and the obesity mouse model induced by the high-fat diet (HFD) was established. In addition, primary cardiomyocytes were purified and identified from the hearts of suckling mice. The 0.8 mmol/L sodium palmitate treatment was used to establish the lipid deposition cardiomyocyte model in vitro. ApoA5-overexpressing adenovirus was used to observe its effects on cardiac function and lipids. The expressions of the fatty acid uptake-related molecules and Mfge8 on transcription or translation levels were detected. Co-immunoprecipitation was used to verify the interaction between ApoA5 and Mfge8 proteins. Immunofluorescence was used to observe the co-localization of Mfge8 protein with ApoA5 or lysosome-associated membrane protein 2 (LAMP2). Recombinant rMfge8 was added to cardiomyocytes to investigate the regulatory mechanism of ApoA5 on Mfge8. The results showed that participants in the simple obesity group had a significant decrease in serum ApoA5 levels (P < 0.05) and a significant increase in Mfge8 levels (P < 0.05) in comparison with the healthy control group. The adenovirus treatment successfully overexpressed ApoA5 in HFD-fed obese mice and palmitic acid-induced lipid deposition cardiomyocytes, respectively. ApoA5 reduced the weight of HFD-fed obese mice (P < 0.05), shortened left ventricular isovolumic relaxation time (IVRT), increased left ventricular ejection fraction (LVEF), and significantly reduced plasma levels of triglycerides (TG) and cholesterol (CHOL) (P < 0.05). In myocardial tissue and cardiomyocytes, the overexpression of ApoA5 significantly reduced the deposition of TG (P < 0.05), transcription of fatty acid translocase (FAT/CD36) (P < 0.05), fatty acid-binding protein (FABP) (P < 0.05), and fatty acid transport protein (FATP) (P < 0.05), and protein expression of Mfge8 (P < 0.05), while the transcription levels of Mfge8 were not significantly altered (P > 0.05). In vitro, the Mfge8 protein was captured using ApoA5 as bait protein, indicating a direct interaction between them. Overexpression of ApoA5 led to an increase in co-localization of Mfge8 with ApoA5 or LAMP2 in cardiomyocytes under lipid deposition status. On this basis, exogenous added recombinant rMfge8 counteracted the improvement of lipid deposition in cardiomyocytes by ApoA5. The above results indicate that the overexpression of ApoA5 can reduce fatty acid uptake in myocardial cells under lipid deposition status by regulating the content and cellular localization of Mfge8 protein, thereby significantly reducing myocardial lipid deposition and improving cardiac diastolic and systolic function.
Animals
;
Humans
;
Mice
;
Myocytes, Cardiac/metabolism*
;
Obesity/physiopathology*
;
Male
;
Apolipoprotein A-V/blood*
;
Lipid Metabolism/physiology*
;
Milk Proteins/blood*
;
Myocardium/metabolism*
;
Diet, High-Fat
;
Antigens, Surface/physiology*
;
Mice, Inbred C57BL
;
Cells, Cultured
;
Female
10.Eccentric treadmill exercise promotes adaptive hypertrophy of gastrocnemius in rats.
Zhi-Qiang DAI ; Yu KE ; Yan ZHAO ; Ying YANG ; Hui-Wen WU ; Hua-Yu SHANG ; Zhi XIA
Acta Physiologica Sinica 2025;77(3):449-464
The present study aimed to investigate the effects of eccentric treadmill exercise on adaptive hypertrophy of skeletal muscle in rats. Thirty-two 3-month-old Sprague Dawley (SD) rats were selected and randomly assigned to one of the four groups based on their body weights: 2-week quiet control group (2C), 2-week downhill running exercise group (2E), 4-week quiet control group (4C), and 4-week downhill running exercise group (4E). The downhill running protocol for rats in the exercise groups involved slope of -16°, running speed of 16 m/min, training duration of 90 min, and 5 training sessions per week. Twenty-four hours after the final session of training, all the four groups of rats underwent an exhaustion treadmill exercise. After resting for 48 h, all the rats were euthanized and their gastrocnemius muscles were harvested for analysis. HE staining was used to measure the cross-sectional area (CSA) and diameter of muscle fibers. Transmission electron microscope was used to observe the ultrastructural changes in muscle fibers. Purithromycin surface labeling translation method was used to measure protein synthesis rate. Immunofluorescence double labeling was used to detect the colocalization levels of lysosomal-associated membrane protein 2 (Lamp2)-leucyl-tRNA synthetase (LARS) and Lamp2-mammalian target of rapamycin (mTOR). Western blot was used to measure the protein expression levels of myosin heavy chain (MHC) IIb and LARS, as well as the phosphorylation levels of mTOR, p70 ribosomal protein S6 kinase (p70S6K), and eukaryotic translation initiation factor 4E binding protein 1 (4E-BP1). The results showed that, compared with the 2C group rats, the 2E group rats showed significant increases in wet weight of gastrocnemius muscle, wet weight/body weight ratio, running distance, running time, pre- and post-exercise blood lactate levels, myofibrillar protein content, colocalization levels of Lamp2-LARS and Lamp2-mTOR, and LARS protein expression. Besides these above changes, compared with the 4C group, the 4E group further exhibited significantly increased fiber CSA, fiber diameter, protein synthesis rate, and phosphorylation levels of mTOR, p70S6K, and 4E-BP1. Compared with the quiet control groups, the exercise groups exhibited ultrastructural damage of rat gastrocnemius muscle, which was more pronounced in the 4E group. These findings suggest that eccentric treadmill exercise may promote mTOR translocation to lysosomal membrane, activating mTOR signaling via up-regulating LARS expression. This, in turn, increases protein synthesis rate through the mTOR-p70S6K-4E-BP1 signaling pathway, promoting protein deposition and inducing adaptive skeletal muscle hypertrophy. Although the ultrastructural changes of skeletal muscle are more pronounced, the relatively long training cycles during short-term exercise periods have a more significant effect on promoting gastrocnemius muscle protein synthesis and adaptive hypertrophy.
Animals
;
Rats, Sprague-Dawley
;
Physical Conditioning, Animal/physiology*
;
Rats
;
Muscle, Skeletal/metabolism*
;
TOR Serine-Threonine Kinases/metabolism*
;
Male
;
Hypertrophy
;
Adaptation, Physiological/physiology*
;
Adaptor Proteins, Signal Transducing/metabolism*
;
Ribosomal Protein S6 Kinases, 70-kDa/metabolism*
;
Intracellular Signaling Peptides and Proteins


Result Analysis
Print
Save
E-mail